Becquerel is a 167 km-diameter crater at 22.1°N, 352.0°E on Mars, in Arabia Terra. Photographs by the Mars Global Surveyor revealed spectacular layered sedimentary deposits in this crater. The layers appear to be only a few meters thick and show little variations in thickness. Recent studies with HiRISE have determined the exact thickness of the layers in Becquerel. The 66 layers measured showed one group of layers to average 3.6 meters and another group to average 36 meters in thicknes. Patterns like this are usually produced on Earth through the effects of water; volcanic deposits would not produce ash or laval flows of such regular thickness and in any event there are no nearby volcanic vents.
There are cyclic variations in the thickness of the exposed sedimentary layers, possibly indicating cyclic variations in environmental conditions while the sediment was being laid down. Most of the layers are parallel to each other, suggesting they formed by vertical settling, but a few are cross-bedded, indicating that at the time that the layers were deposited the sediment was transported along the ground surface by wind or water. The sedimentary material appears to be easily eroded and active wind erosion may be continuing to the current day.
It is named after Antoine H. Becquerel.
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